A zeolitic imidazolate hybrid membrane (Co-IM-mIM) containing two imidazolate ligands deposited on a macroporous α-alumina support was prepared by pre-depositing and secondary growth technique.XRD,TGA and SEM characterizations demonstrate that a stable and thin,but dense and pure-phase Co-IM-mIM membrane can be obtained on the macroporous-alumina discs in Teflon-lined autoclave at 120 ℃ after pre-depositing by dip-coating at room temperature.No visible cracks,pinholes or other defects were observed on the membrane layer.The gas separation studies of Co-IM-mIM membrane were carried out at 25 ℃ and 1 × 105 Pa,showing ideal selectivity of 6.95,5.25,3.40 for H2/CO2,H2/N2 and H2/CH4,respectively,and a permeance of 17.37×10 6 mol/(m2.s.Pa) for H2.The influence of temperature and trans-membrane pressure on hydrogen separation and permeation was also carried out.The gas permeation and selectivity demonstrate that this membrane may have potential applications for efficient H2 separation.